1. Field of the Invention
This invention relates to a weldless shock absorber for use in an automotive vehicle.
2. Disclosure Information
The outer housings of automotive shock absorbers and struts have typically comprised a plurality of mild steel stampings fastened to each other by various welding processes. The mounting brackets for such shock absorbers have also been welded to the body of the shock absorber either by fusion welding or spot welding techniques. Examples of welded brackets are shown in U.S. Pat. Nos. 4,054,312 and 4,509,781. The shock absorbers disclosed in these patents are used for automotive bumpers. An important feature of shock absorbers used for this purpose is the ability to retain the shock absorber in its proper position notwithstanding the imposition of severe axially directed loads. During either a frontal or a rearward impact of a vehicle with either a stationary or a moving object, the bumper is moved inwardly against the resistance provided by the shock absorber.
It has been found through repeated testing that the weakest structural members in a typical shock absorber are the welded joints. In a conventional shock absorber, the mounting bracket is typically secured to the outer cylinder of body with a welded joint. The present invention produces significantly stronger joints for connecting the major components, especially the mounting bracket and outer cylinder, into an improved shock absorber.
Weldless joints have been used for certain of the fastening requirements in automotive shock absorbers. Examples of such joints used for the purpose of retaining the upper piston rod bearing within the shock absorber or strut are shown in U.S. Pat. Nos. 4,482,036, and 4,491,160, as well as in copending U.S. application Ser. No. 816,584. None of these disclosures, however, either teach or suggest the use of a weldless joint to attach the mounting bracket of an automotive shock absorber.
The present invention utilizes a weldless retention system for maintaining the mounting bracket on the outer tube of a shock absorber. This weldless system includes one or more outwardly extending annular rings integrally formed from the shock absorber's outer cylinder. U.S. Pat. Nos. 1,656,222 and 3,314,276 disclose annular rings formed for the purpose of providing a pipe fitting. It is also known to provide an annular ring for locking components of automotive exhaust mufflers together. An example of such a joint is disclosed in U.S. Pat. No. 4,565,260. Such annular rings, have not, however, been employed in the configuration described herein and could not function as a structure for retaining the mounting bracket of an automotive bumper shock absorber against the force arising in a high energy impact of the vehicle.